Which vascular supply relates to contralateral face and arm weakness greater than leg during a stroke?

The middle cerebral artery is responsible for supplying blood to significant areas of the lateral aspect of the cerebral hemisphere, which includes the motor and sensory areas associated with the face and upper limb. A stroke affecting this artery typically results in contralateral weakness and sensory loss, especially impacting the face and upper extremity more than the lower extremity.

This phenomenon occurs due to the homunculus arrangement in the motor cortex, where the regions that control the face and arm are located more laterally compared to those that govern the leg. Thus, when an ischemic event or hemorrhage affects the middle cerebral artery, it leads to a predominant weakness in the face and arm on the side opposite to the stroke, often noted as greater than that observed in the leg.

The other vascular supplies listed do not present this specific pattern. The anterior cerebral artery primarily supplies the medial portions of the frontal lobes and the superior medial parietal lobes, leading to leg weakness if affected. The posterior cerebral artery provides blood to the occipital lobes and inferior parts of the temporal lobes, mainly affecting vision and some sensory modalities. Lastly, the vertebrobasilar arteries supply the brainstem and cerebellum, which can manifest as different symptoms, such as motor